Spring units

ABSTRACT

A spring unit ( 2 ) for incorporation into a bed, divan bed, mattress, or other upholstery unit comprises a first spring ( 4 ) and a second spring located ( 6 ) within said first spring ( 4 ). The first spring ( 4 ) may be a pocketted spring, or the second spring may be a pocketted spring, or both of said springs may be pocketted springs, the pockets of said pocketted springs being composed of a woven material and/or a synthetic material.

BACKGROUND OF THE INVENTION

1. Field of Invention

This invention relates to spring units and more particularly to springunits for beds, divan beds, mattresses, and other upholstery units. Suchbeds etc will be hereinafter referred to as ‘sprung units’.

2. Description of the Related Art

Sprung units are conventionally made in differing degrees of hardness,this usually being achieved by varying the number of springs per unitarea—generally known as ‘the spring count’—of the sprung unit, or bychanging the gauge of the wire from which the springs are made. Suchvariation in the manufacturing procedure, i.e. the incorporation ofdiffering numbers of springs or changing the wire gauge, complicates themanufacturing procedure and consequently increases the manufacturingcosts.

It has previously been proposed to incorporate a second spring within afirst spring so as to form a double spring unit whereby the springs arecompressed in stages so as to lessen the shock on the sprung unit when aperson sits or lays upon the sprung unit, Examples of such spring unitsare shown and described in U.S. Pat. Nos. 1,192,510 (Fischmann),3,031,690 (Ramsey), and 2,631,840 (Bugenhagen). However, in suchprevious proposals, the second spring has been connected, eitherdirectly or indirectly, to said first spring such that the second springhas not been freely movable within said first spring, which placesrestrictions on the sprung unit in use.

SUMMARY OF THE INVENTION

The present invention therefore seeks to provide an improved form ofspring unit which will obviate the disadvantages of known spring units.

According to the present invention there is provided a spring unit forincorporation into a bed, divan bed, mattress, or other upholstery unitcomprising a first spring and a second spring located within said firstspring, said second spring having no connection to said first spring soas to be freely movable within said first spring.

Preferably, the length of said second spring will be less than that ofsaid first spring.

In an embodiment of the invention, the first spring may be a pockettedspring, and in an alternative embodiment of the invention the secondspring may be a pocketted spring. In yet a further alternativeembodiment, each of said first and second springs may be pockettedsprings.

The pocket of the or each pocketted spring may be composed of a wovenmaterial such as calico which is sewn in order to form the pocket(s).Alternatively, the pocket(s) may be composed of synthetic material whichis sewn or sonic or heat welded in order to form the pocket(s). Whereboth springs are pocketted springs, both pockets may be composed of awoven material or both may be composed of synthetic material, or thepockets may be formed one of each material, the pocket of woven materialpreferably being around said first spring.

According to another aspect of the present invention there is provided asprung unit incorporating a plurality of spring units, each of saidspring units comprising a first spring and a second spring locatedwithin said first spring.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the invention may be more readily understood, embodimentsof the invention will now be described, by way of example only,reference being made to the accompanying drawings, wherein:

FIG. 1 is a view of a spring unit according to a first embodiment of theinvention;

FIG. 2 is a view of a spring unit according to a second embodiment ofthe invention;

FIG. 3 is a view of a spring unit according to a third embodiment of theinvention;

FIG. 4 is a view of a further embodiment of a spring unit according tothe invention; and

FIG. 5 is a view of a sprung unit, partly cut away, to show theincorporation of a plurality of spring units.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings and firstly to FIG. 1, there is shown a springunit which is indicated generally by reference numeral 2 and whichcomprises a first, outer spring 4 and a second unconnected, inner spring6. As will be seen, the length of the inner spring is less than thelength of the outer spring 4, and the pitch of the spring 6 is less thanthat of the spring 4.

The inner spring 6, captive within the outer spring 4, is movablelongitudinally within the outer spring 4 between the end 4A and theother end 4B of the spring 4.

Referring now to FIG. 2, it will be seen that the outer spring 4 and theinner spring 6 are located within a single pocket 8—so as to form apocketted spring A—in engagement with the outer spring 4. The pocket isformed by longitudinal lines of retention 10 and 12 and by lateral linesof retention 14 and 16.

The pocket 8 may be composed of a woven material such as calico, inwhich case the lines of retention will be formed by sewing.Alternatively, the pocket 8 may be composed of a synthetic material, inwhich case the lines of retention may be formed either by sewing or bymeans of sonic or heat welding.

As with the spring unit of FIG. 1, the inner spring 6 is movable withinthe pocket 8 of the outer spring 4, as shown in FIG. 2.

FIG. 3 illustrates a spring unit 2 in which the inner spring 6 islocated within a pocket 20—so as to form a pocketted spring B—which iscomposed of either a woven material such as calico, in which case thepocket will be secured in position around the spring 6 by sewing, oralternatively of synthetic material, in which case the pocket 20 will besecured in position around the spring 6 either by sewing or by sonic orheat welding. The pocketted spring B, formed by the pocket 20 and thespring 6, is as in the embodiment of FIGS. 1 and 2, movablelongitudinally between the end 4A and the end 4B of the outer spring 4.

Referring now to FIG. 4, there is illustrated a ‘composite’ pockettedspring unit which is a combination of the spring units of FIGS. 2 and 3.Thus the spring unit of FIG. 4 comprises an outer pocketted spring A andan inner pocketted spring B, and for ease of identification, thereference numerals of FIGS. 2 and 3 have been applied to FIG. 4. Theinner pocketted spring B is movable longitudinally within the outerpocketted spring A from one end 4A to the other end 4B of the outerpocketted spring A.

The pockets of the pocketted springs A and B may both be composed of awoven material such as calico, or both may may be composed of asynthetic material, or there may be one of each, in which case it ispreferred that the pocket of pocketted spring A is composed of the wovenmaterial.

In use, and referring to now to FIG. 5, which illustrates part of sprungunit 22, it will be seen that the unit incorporates a plurality—two areindicated—of the spring units as shown in FIG. 4, i.e. the compositepocketted spring unit. The spring units 2 are located between upper andlower layers of padding 24 and 26 and side walls 28 and 30, the springunits being held in position in conventional manner.

The sprung unit 22 may be formed wholly of spring units in accordancewith the invention, or alternatively a plurality of spring units inaccordance with the invention may be used in conjunction with or incombination with a plurality of conventional pocketted springs, orindeed with other suitable types of conventional and known springs.

Thus the invention provides a spring unit 2 and a sprung unit 22 whichincorporates a plurality of said spring units 2 wherein, in use of thesprung unit 22, the outer spring 4 will be partially compressed firstfollowed by compression together of the outer spring 4 and the innerspring 6, the amount of compression of the spring(s) being dependentupon the weight of the user.

Thus there is provided a sprung unit, i.e. a bed, divan bed, mattress orother upholstery unit, whose degree of hardness is variable—dependingupon the amount of compression of the springs of the sprung unit—andtherefore it will not be necessary to manufacture ‘hard’ sprung unitsand ‘soft’ sprung units by varying the ‘spring count’ of the unit, such‘spring count’ automatically being adjusted and established by the userof the sprung unit.

Finally, it will be appreciated that whilst parallel springs and springunits have been described and illustrated, the invention is equallyapplicable to barrel shaped and other shaped springs and spring units.

What is claimed is:
 1. A spring unit (2) for incorporation into amattress, said mattress having a first surface and a second surface, andsaid spring unit comprising a first spring (4) having a first end and asecond end, and a second spring (6) having a first end and a second end,said second spring being located within said first spring (4) and havingno connection to said first spring (4) so as to be freely movable withinsaid first spring (4) from the first end of said first spring to thesecond end, wherein in a first position of the mattress the first end ofthe second spring (6) is adjacent the first end of the first spring (4)and the first surface of the mattress, and in a second, reversedposition of the mattress, the first end of the second spring is adjacentthe second end of the first spring (4) and the second surface of themattress.
 2. A spring unit according to claim 1, wherein the length ofsaid second spring (6) is less than that of said first spring (4).
 3. Aspring unit according to claim 1 or claim 2, wherein said first spring(4) is a pocketted spring (A).
 4. A spring unit according to claim 1 orclaim 2, wherein said second spring (6) is a pocketed spring (B).
 5. Aspring unit according to claim 3, wherein said first pocketted spring(A) comprises springs (4,6) located within a pocket 8 of woven materialor synthetic material.
 6. A spring unit according to claim 5, whereinsaid pockets (8,20) of woven material or synthetic material are formedby sewing, heat welding or sonic welding.
 7. A bed, divan bed, mattress,or other upholstery unit incorporating a plurality of spring unitsaccording to claim
 1. 8. A spring unit according to claim 3, whereinsaid second spring (6) is a pocketed spring (B).
 9. A spring unitaccording to claim 4, wherein said first pocketted spring (A) comprisesa spring (4) located within a pocket (8) of woven material or syntheticmaterial and in that said second pocketted spring (B) comprises a spring(6) located within a pocket (20) of woven material or syntheticmaterial.
 10. A spring unit according to claim 9, wherein said pockets(8,20) of woven material are formed by sewing, heat welding or sonicwelding.
 11. The bed, divan, mattress or other upholstery unit accordingto claim 7 further comprising reversible sides, wherein said pluralityof spring units are arranged so that said bed, divan, mattress or otherupholstery unit provides a same degree of variable hardness irrespectiveof which particular side is in contact with a user.
 12. A bed, divan,mattress or other upholstery unit incorporating a plurality of springunits each comprising a first pocketted spring (A) having two ends and asecond pocketted spring (B) located within said first pocketted spring(A), wherein said second pocketted spring (B) has no connection to saidfirst pocketted spring (A) so as to be freely movable within said firstpocketted spring from one end of said first spring to the other end.